Recently, with the spread of IC cards, there are many more opportunities of using IC cards. For example, in a shop, credit settlement with a credit card can be used. Credit settlement is carried out using a credit processing apparatus and a personal identification number input apparatus connected for communication with the credit processing apparatus.
The personal identification number input apparatus has a card reader and a personal identification number input unit. The personal identification number input apparatus sends card information read from a credit card loaded in the card reader and a personal identification number inputted by a shopper with the input unit, to the credit processing apparatus. The credit processing apparatus executes credit settlement on the basis of the received card information and personal identification number, and inputted article information of a purchased article.
As an apparatus having a card insertion port as in the personal identification number input apparatus, there is an apparatus having a card-leaving prevention function. For example, JP-UM-A-4-98776 discloses a data processing apparatus having a detection unit which detects a card inserted in a card insertion port and notifies that the card is left behind on the basis of the result of the detection by the detection unit.
The card-leaving prevention function of the conventional personal identification number input apparatus is realized by displaying a predetermined message on a display device or buzzing to warn the card owner that the credit card is left behind, as in the data processing apparatus disclosed in JP-UM-A-4-98776.
However, since the warning is given immediately after settlement is completed, there is a probability that a card owner who remembers to remove the card may feel uncomfortable.